1.0

Purpose:

A Transformation Layer of the Overberg DMA was prepared as part of the Overberg Fine Scale Biodiversity (FSB) Project, which will be used for Systematic Conservation Planning in the area. Land cover is one of the most important information layers used in a conservation assessment. As transformed areas are generally considered to have very little biodiversity value, a land cover map tells us how much biodiversity is left and where this is located.

Copyright holder C.A.P.E.

Base data for the transformation map was the WC Fields layer, which was clipped to the Overberg DMA. Additionally, road data from the CD:SM for the extended planning domain was buffered by 50 metres for major roads, and 25 metres for minor roads. This buffered roads data was then clipped to the Overberg Planning Domain, and unioned to the Fields layer. Were the road data and field data

intercepted, the road attribute data replaced the underlying farm data. The unioned dataset was then dissolved, to simplify it. This simplified dataset was then unioned to an Overberg DMA layer, to provide “background” polygons for digitising. Detailed transformation data from the Agulhas Biodiversity Initiative was also incorporated. ABI transformation data was clipped out of the ABI Transformation Layer by using unclassified polygons in the Overberg Transformation Layer (above), under the assumption that the WC Fields layer and the roads layer were sufficiently accurate, and more up to date, and would reflect any new land use transformation to agriculture.

This base layer was refined by heads up digitisation from 2005 SPOT5 satellite imagery. Initial splitting and classification of polygons focussed on large areas, and their interface with transformed

SANS 1878

FGDC-STD-001-1998